Flat tubeless ionization conductor device



Sept. 29, 1931. HQTCHNER 1,825,399-

FLA'I TUBELESS IONIZA'I'ION CONDUCTOR DEVICE Filed June 26. 1929 3 Sheets-Sheet 1 Sept. 29, 1931. F. HOTCHNER 1,

FLAT TUBELESS IONIZATION CONDUCTOR DEVICE Filed June 26, 1929 3 Sheets-Sheet 2 Sept. 29, 1931. F. HOTCHNER FLAT TUBELESS IONIZATION CONDUCTOR DEVICE 5 Sheets-sheet 3 Filed June 26. 1929 IN VENTOR Patented Sept. 29, 1931 FRED HOTCHNER, L08 ANGELEB, CALIFORNIA FIAT TUBELESS IONIZATION CONDUCTOB DEVICE Application fled June 86,

This invention relates to a vacuous electric device and in the embodiment of the invention here shown it is illustrated by a fiat tubeless ionization conductor device such as a discharge tube display. It is to be un-- derstood that the invention is not limited to the particular application here shown but is applicable to the construction of devices for numerous other stance, therapeutic apparatus, illuminating 'units, thermionic apparatus and scientific glassware.

One object of the invention is to provide a flat artlcle of vitreous material having a tortuous channel therethru for the passage of a discharge, which when completed is composed substantially entirely of vitreous material.

It is a further object to provide a novel means of tubulating a vitreous structure of the general class described in order to provide means of evacuating the same.

It is another object to provide a flat article of vitreous material having a tortuous passage therein which passage crosses over itself or traverses a course such as to make it parallel itelf with very slight clearance.

In the embodiment of the invention here shown an ionization conductor display is provided by a structure formed of two sheets of glass or other similar material, a tortuouspathway for the discharge being provided' therebetween. Where the pathway for the discharge returns over itself novel means are provided to form the passageway so as to make it appear as'a single passage and permit a sturdy construction.

It is an object to provide a construction in a transparent ionization conductor device in which the discharge starts at any desired point and stops at another desired point ,without any apparent connection with the edges of the device.

It is an object to provide a device of the class described which may be made entirely of transparent material, which will be of considerable strength, will be self-sup orting and suitable as a complete electrica device with no additional elements necessary other purposes such as, for in- 1999. Serial No. 378,858.

than a mounting and a contact to supply the necessary current, and which will be of very little thickness as compared with any other equivalent device in the art.

It is a further object to provide a method of manufacturing a vitreous article having a tortuous passage therethru crossin over itself or running superposed over itsel from only two sheets of material. 1

It is"a further object" to provide an ionization conductor lamp in which the discharge appears to completely fill out the passage and in which the effect of striations and concentrated twisting discharge columns is overcome giving a uniform and steady appearance to the display in cases when these actions are present;

The invention provides a practical commerical means 0 manufacturing *vacuum electric devices in quantity and at a relatively low cost and makes possible the construction of devices that are usually prohibitive in cost if made by the former methods.

The type of vacuum seal here provided is of such nature as to allow considerable choice in the particular method of sealing together the plates. Leakage in order to occur must take a long path between the plates and hence while I prefer to make use of a vitreous seal,

other types of seals might be selected by taking advantage of the restrictive efiect of a long leakage path and the self-purifying effect of certain types of vacuum electric devices. Thus a resinous seal might be used in some cases in which the requirements are not severe. In other cases bakelite might be used as a sealing medium.

A further object is to provide a structure having a plurality of separate pathways for discharges, .which may, if desired, be made to cross over each other, or have dilferent aseous conductors therein thereby providmg for illumination from the separate pathwa s of difierent colors.

ther objects have to do with various features which will hereinafter be more fully described and set forth in the appended claims.

Several embodiments of the invention are, shown in the accompanying drawings inv which the same reference numeral refers to the same part wherever used in more than one figure.

Figure 1 is a front view of an individual letter unit for an advertising display.

Figure 2 is a cross-section of the device shown in Figure 1 taken on the line 2-2.

Figure 3 is a cross-section of the device shown in Figure 1 taken on the line 3-3.

Figures 4 and 5 are views of the two main elements of the device shown in Figure 1 before assembling, the near faces of the elements being shown in the views to illustrate the grooves which form the discharge passa e.

igure 6 is an enlarged cross-section, taken on the line 33 in Figure 1, of the central portion of the device showing the method of insulating from each other the two portions of the discharge passage where it is superposed upon itself.

Figure 7 is a cross sectional view of a device similar to that shown in Figure 1 in position in a press at a certain stage in the process of manufacture which is described below as an illustration of one method of fabricating the devices of this invention.

Figure 8 is an illustration of one method of forming the grooves in the main elements of the device of this invention.

Figure 9 is a crosssectional View of one of the electrodes taken on the line 9-9, Figure 1.

Figure 10 is a front view of a modified form of this invention in which the discharge passage crosses over itself twice. A portion of a sign here is shown broken way from the remainder.

Figure 11 is a view of the back element of the device shown in Figure 10 to show the grooves.

Figure 12 is a view of the front element of the device shown in Figure 10 to show the channels. In this view as well as that in Figure 11 the faces shown are those which are brought together in the assembly.

Figure 13 is a perspective of a portion of the sheet shown in Figure 12 illustrating the construction of the channels.

Figure 14 is a view of one form of this invention in which two se arate discharge passages are provided in a single structure which may if desired have different color characteristics when provided with suitable ionization conductors. A

Figure 15 is a perspective View of a portion of the back element of the device shown in Figure 12.

Figure 16 is a perspective view of a portion of the front element of the device shown in Figure 14, corresponding to the piece shown in Figure 15. In this view as well as well as that shown in Figure 15 the faces shown are those that are brought together in assembly.

. pletely self supporting,

One form which this invention may take when applied to the art of illuminating devices is shown in Figure 1, in which an individual luminous letter is illustrated. This letter when assembled in a display makes an unusually attractive unit. The unit is comwhenfinished being practically one solidpiece. It is practically entirely transparent, and the discharge terminates abruptly at the ends of the letter having no connecting portion to the edges or to adJacent letters as is common in the art at the present time. The thickness of the unit is so slight as compared with the other dimensions and the superposed portions of the discharge passage being so close together as to practically entirely overcome the an lar abberation now common with formed tu ing, that the device possesses decided commercial advantages over the prior art devices.

The letter unit is indicated by the numeral 1, and is formed from the two sheets of dielectric material 2 and 3, at least one of which is permeable to rays of light. When used in a display without a background structure I prefer to have both sheets of material trans- =parent. When the units are assembled with a background or in a double faced sign, as an illustration, I prefer to finish the rear surface 30 of the sheet 3 in such manner as to reflect the light rays all towards the front and thus increase the luminous efliciency of the sign. A mirror coating is suitable for this purpose for certain types of installations, the unit itself serving as an excellent protection for the silvering.

On one side of the sheet 2, the grooves 4, 5, 6, 7, 8, 9 and 10 are formed in a definite relation to other grooves, 11, 12, 13, 14, 15, 16 and 17, formed on one side of the sheet 3. Upon the assembly of the unit the grooves 9 and 16 together form the chamber for one of-' the electrodes, 41; the grooves 4 and 11 form the chamber for the other electrode, 42; the grooves 10 and 17 form the passage way for the tubulating stem 89; and the grooves 8, 15, 7, 14, 6, 13, 5 and 12 form the discharge passage, in which the luminous radiation is generated by the passage of a current thru a suitable ionization conductor.

The grooves 5, 6, 7, 13, 14 and 15 each have a portion which is undercut when formed leaving an overhanging lip extending from the edge over the groove. The lips are indicated by the numerals 20, 21, 22, 23, 2 4 and 25, respectively. Each lip is spaced a short distance from the end of the groove over which it extends, leaving the ends of the grooves, indicated by 31, 32, 33, 34, 35

As indicated in Figure 6, the ends'of the lips meet at a plane 37, there being ample mass of material in the lips to permit the application of suificient pressure at this plane to effeet a discharge tight joint, if such is necessary in the particu ar process of fabrication used in any particular case. As in some cases it might not be desired to effect a seal by pressure but to depend. on a mechanically close fit, the design of this detail is such as to provide a dependable and substantial mechani-' cal fit.

The type of electrodes shown is that which I have disclosed in several copendin applications for patents on discharge w e electrodes. It is to be understood that this invention is not limited to the use of this particular type of electrode, but I prefer this type for the reason that it provides an ex-' ceedingly small electrode for a given current passage and one which meets the requirements of this application well. In this particular type of electrode, an orifice is provided between the positive column discharge chamber and the electrode chamber. This orifice is here provided by so forming the grooves as to leave opposing ridges 38 and 39, as indicated in Figure 9, thus providing a semi-circular constricted orifice 40 between the electrode chamber 4 and the end of the positive column discharge passage formed by the grooves 5 and 12. The semi-circular tubular electrode 42 has an orifice 44, and is positioned in the. chamber 4 with the orifice 44 opening thru the orifice 40 into the positive column chamber. This electrode may be made of any suitable conducting material, but I prefer to use a wire mesh in order that it may be to some extent transparent. The lead-in conductors 45 and 46, Figure 1, extend from the electrodes 41 and 42 to the terminal strips 47 and 48. As the current consumed by ionization conductor lamps is of very low amperage, this conductor may be very fine and inconspicuous. To render it more difficult of detection it may be in the form of several very fine wires running parallel and spread apart.

A suitable method of forming the grooves is shown in Figure 8 in which 49 indicates a sheet of material in process of formation and having a layer of sand blast resisting material 50 on the surface which is being grooved. Openings are formed thru this layer of protective material wherever the grooves are to be cut. The undercut portions are formed by a diagonal blast of sand thru the openings such as 51. The sand blast nozzle is indicated by 53.

One method of sealing the elements together is shown in Figure 7. Here two sheets of material 54 and 55, previously grooved are assembled in a press, the table of which is indicated by 56 and the head of which is indicated by 57. The two part flat die is indicated by 58 and 59, each part being provided with an electric heater element 60 and 61. Before placing in the die the element is provided with the electrodes indicated by 62, lead-in conductors, length of tubing 64 is placed in the tubulator channel 65 with the inner end opening into the positive column discharge passage 66. A protective clamp 67 is provided in connection with the die for the purpose of preventing the collapse of the tube 64 from the heat.

In the preferred form of this invention the unit is made from glass, the tubulating tube also being of glass and the method of sealing the glass parts together being to raise them to a temperature suflicient to render them adhesive to each other, but not sufficient to cause the glass to lose its form. A slight pressure applied at the point of sealing temperature pushes the surfaces together. Air pressure is applied in the tubulating tube to force it against the walls of the tubulator channel.

I prefer also to carry out the process of treating and filling the device while still in the die, the process of purifying the walls of the passage being simplified by the fact that the glass is already at a temperature suflicient to permit the drawing out of impurities by the pump. The device is finally sealed by fusing and parting the tubulating tube as indicated by 19, Figure 1. Numerous variatigps on this method of fabrication are pos- S1 e.

In Figure 10 a port-ion of an advertising display made according to this invention is shown in which the discharge passage crosses over itself in two places. The device, indicated by 70, has a discharge passage, indicated by 71, which crosses over itself at two points 72 and 73. The back sheet of material 74, shown in Figure 11, has the grooves 75, 76 and 77. The front sheet 78, shown in Figure 12, has the. two channels 79 and 80 formed thru the body of the material and opening to the surface at the points 81, 82, 83 and 84 forming in the order given the connections between the end of the groove and the be ginning of the groove 76, and the end of the roove 76 and the beginning of the groove 7. An enlarged perspective view of the portion of the sheet 78 having the channel passing thru it is shown in Figure 13.

Various methods may be used for forming thegrooves and channels in the sheets. I prefer the use of a sand blast as being a practical and rapid process, and also because it leaves the surface of the walls of the grooves in a roughened condition so as to form a diffusing medium around the column of luminous gas. As positive column discharges often have dark spaces or striations and under some conditions become contracted and wormy this diffusing medium serves to make the discharge appear of the full diameter of the passage, continuous and steady.

indicated by 63, and a Furnishing the walls of the chamber with a diffusing surface has a further advantage in that it renders the characters clearly discernible when not illuminated, as otherwise the entire body being transparent and very little diffusion of incident light taking place within the device it would have little readability unless lighted. This applies equally well whether or not the rear of the device be given a reflecting surface.

In the View in Figure 14 a display is shown in elevation in which two distinct and separate discharge passages are provided in the form of ornamental borders crossing each other at numerous oints. Thesebordersmay be characterized y radiation in different parts of the spectrum by'filling them with different kinds of conductors.

The device is indicated by the numeral 90; the passages by 91 and 92; each of said passages being provided at the ends with electrode terminals indicated by 93 and 94, and 95 and 96, respectively. The lead-in conductors 97, 98, 99 and 100 provide connection between the electrodes and the contact strips 101, 102, 103 and 104. The passage 91 is evacuated and charged by means of the tubulator 105, and the passage 92 is conditioned by means of the tubulator 106.

The view in Figure 15 is of a portion of the back sheet 107 of the device 90 such as might be broken from the upper left hand corner of the device shown in Figure 14. The passage 92 is formed by grooves, 108, 108, etc., and connecting channels, 109, 109, etc., formed from the contacting face 110. The front sheet 111, shown in Figure 16, corresponding to the view in Figure 15, has a continuous groove, 112, forming the passage 91, this passage crossing the passage 92 at the points 113, 113, etc.

Thus a very unique and attractive type of display is produced. The two borders may be charged with different gases and flashed separately. The space in the center of the panel may be used for lighted copy.

In the practice of the method of fabrication illustrated by the view in Figure 7, the .glass should be raised to a temperature sufiicient to render it adhesive to itself but not sufficient to cause plastic flow in the articles under the conditions present in the die. The permissible temperature can be controlled by regulating the pressure within the article by means of the tubulator stem. If the sheets are at the beginning sufficiently true and thesides are parallel, a very slight pressure should suffice to effect the seal. A test for leaks can be made without removing the work from the die. The processing of the tube preparatory to charging with the conductor can be also carried forward in the die taking advantage of the high temperature of the work after sealing to facilitate the bombarding of the walls and the removal of impurities. The

work can be if desired buried in heat insulating material or placed in an annealing oven after taking out of the die.

The invention is not limited to the particular devices shown or the methods set forth but may be applied in numerous ways within the purview o the claims, and is limited only by the prior art and the limitations imposed by the claims. I

Having thus described my invention altho without attempting to set forth all of the forms which it might take, or all of the applications in the various arts and industries to which it might be put, what I claim is;

1. In an electric device, two sheets of dielectric material forming a discharge-guiding structure, grooves in the joining faces of sa1d sheets of material forming upon'the assembly of said sheets a continuous tortuous passageway therebetween, the said passageway being essentially superposed over itself in at least one portion of its path, the opposing grooves at the said superposed portion being formed with openings to the contacting surfaces of the sheets staggered with respect to each other so that upon the joining of said sheets each groove at the superposed portion of the path is separated from the opposing groove by a region of contact between the joining faces of the said sheets.

2. In an electric device, a structure including two sheets of dielectric material having grooves in the near faces thereof forming upon the joining of said sheets a continuous tortuous passageway therebetween, the said passageway crossing over itself in at least one point, and a bridge of dielectric material between the openings at the crossing points.

3. In a vacuum electric device a pair of sheets of dielectric material having a groove in the'near face of at least one of said sheets forming upon the assembling of said sheets a passageway for a discharge, and a depression in the face of at least one of said sheets of material for the reception of an electrode there being a constricted passage between the first said passage and the electrode chamber so formed.

4. A unitary, flat, ionization conductor device formed from two sheets of dielectric material, there being recesses in the near faces of said sheets forming upon the assembly thereof a continuous tortuous passage therebetween crossing over itself in at least one place and a bridge of the material of one of said sheets at said crossing place for the purpose of separating the two portions of the said passage at said crossing place.

5. In a vacuum electric device, a pair of sheets of dielectric material, forming a discharge guiding structure, sealed to each other in a vacuum tight joint over an extended area, and leadin conducting means extending into said structure, between said sheets in the plane of said joint.

l- 6. In an-electric device, a pair of sheets of formed, said passa dielectric material joined together with an air tight seal over extended areas of one surface of each thereof, formations in the joiningsfaces of said sheets forming upon the assembly thereof a chamber within the structure so formed, electrodes within said structure at the ends of said chamber, and conducting means extending from said electrodes to the outside of said structure between said sheets and sealed therein.

7 In an electric device, a pair of sheets of dielectric material joined together with an air tight seal over extended areas of one surface of each thereof, there being a formation in the joining face of at least one of said sheets forming upon the assembly of said sheets a chamber within the structure so formed, electrodes at the ends of said chamber, and conducting means extending from said electrodes to the outside of said structure between said sheets and sealed therein.

8. A discharge tube composed of two sheets of dielectric material, there being a formation in the joining face of at least one of said sheets forming upon the assembly of said sheets a chamber within the structure so formed, said sheets being joined together with an air tight joint completely surrounding said chamber, an electrode within said chamber and conducting means extending from said electrode thru the seal formed by said sheets.

9. In an electric device, a pair of sheets of dielectric material having formations from the joining faces thereof which upon the assembly of said sheets form a continuous tortuous passage within the structure so formed said passage crossing over itself in at least one place, said passage at said crossing point taking the form of a duct extending between and connecting the ends of two of the aforesaid formations from the joining face thereby providing a bridge of the material of the sheet in whichsaid duct is formed to isolatethe two portions of said passage at said crossing point. v

10. In an electric device, a pair of sheets of dielectric material having formations from the joining faces thereof which upon the assembly of said sheets form a plurality of tortuous passages within the structure so formed, said passages crossing over each other at least at one place, one of said passages at said crossing point taking the form of a duct extending between and connecting two of said formations from the joining face of the sheet in which said duct is formed providing a bridge of the material of said sheet to isolate the passages from each other.

11. In an electric device, a pair of sheets of dielectric material having formations from the joining faces thereof which upon the assembly of said sheets form a plurality of tortuous passages within the structure so crossin over each other and being isolate .from 'eac other at said crossmg points, and communications from said passages to the edge of said structure thru which said passages may be evacuated,-

said communications being formed thru grooves in the meeting faces of said sheets,

each of the said passages in crossingover the other passages at least in one place being to the outside of the other passages with respect to the edge of said structure whereby said communications extend direct from said passages to the edge of said structure without crossing any other of said passages.

12. An ionization conductor device consisting of an extended body of transparent material within which is formed a passage having a distinctive character other than the general form of the said device, said passage being provided with an ionization conductor and suitable means to pass a-current therethru to cause the same to become luminous, the inside walls of said passage being characterized by a light scattering quality whereby striations in the discharge thru said passage are rendered inconspicuous.

13. An ionization conductor device consisting of an extended body of transparent material within which is formed a passage having a distinctive character other than the general form of the said device, said passage being provided with an ionization conductor and suitable means to pass a current therethru to cause the same to become luminous,

the inside walls of said passage being char- 1 acterized by a light scattering quality whereby said passage is discernible by incident light when said device is not illuminated.

14. A device of the character described formed from two sheets of dielectric materialhaving grooves formed in the meeting faces thereof forming upon the assembly of said sheet a continuous passage in the form of a distinctive character said passage returning over its course in at least one place as regards the appearance on a lineof 'view perpendicular to the plane of the joint formed by the two sheets, said grooves'at the said doubled portion of the passage opening to the surface of their respective sheets in staggered relation to each other so that the unformed surface of each of said sheets closes the groove of the opposite sheet at said doubled over portion of the passage.

15. In a device of the character described, two sheets of dielectric material having grooves in the meeting faces thereof which upon the assembly of said sheets form a continuous tortuous passage within the structure so formed, said passage overlapping place taking the form of an inclined groovev '15 opening against the p '1,sao,ae'o

with the opening thereof to the surface of the .sheet in contactwith the surface of the op} posits sheet and closed thereby.

16; In a device of the character described, two sheets .of dielectric material havin grooves in the meeting faces thereof whic upon the assembly of said sheets form a continuous tortuous passage within the structure so formed, said passage overlapping itself in portions in opposite sheets at at least one lace with respect to a line of view perpendicular to the meeting faces of said sheets, the grooves at said overlapping place having openings offset with respect. to each other an aneface of the opposite sheets except atone end of each of said grooves where said grooves open into each other.

17. In a device of the character described,

= a transparent body formed of a plurality of sheets of dielectric material having formations in the meeting faces thereof which upon the assembly of said sheets form a continuous passage within said body, there beingan ionization conductor within said passage and electrodes at the end of said passe e and conducting means extending from said electrodes to the outside of said body, said electrodesbeing of open construction whereby to be comparatively undiscernable.

In testimony whereof, I aflix my signature.

FRED HOTGHNER. 

